Among conventional methods for recovering CO2, there is a wet process to capture CO2, which comprises passing CO2 through an amine based solution to absorb CO2 and regenerating the solution in a regeneration column. Such wet process has a problem of generating waste water.
In order to solve the above problem, a dry process has been developed which typically separates and recovers CO2 by using a double columns type reactor to permit CO2 gas in the exhaust gas to be homogeneously in contact with a dry solid absorbent and selectively capture only CO2.
Conventional processes and techniques known in the art have disadvantages in that it is difficult to control temperature between the recovery reactor and the regeneration reactor, and the recovery reactor shows low CO2 removal efficiency and less use of absorbents.